package com.hns.tool.pub;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.NetworkInterface;

/**
 * 获取客户端的mac地址
 * @author:JeffXu
 * @email:835264047@qq.com
 * @version Revision 2.0.0
 */
public class ClientMacAddr {
    
	/**
	 * 目标主机名
	 */
    private String         sRemoteAddr;
    
    /**
     * 目标主机端口
     */
    private int            iRemotePort = 137;
    
    /**
     * byte数组做缓冲数据
     */
    private byte[]         buffer      = new byte[1024];
    
    /**
     * 数据报套接字
     */
    private DatagramSocket ds          = null;
    
    /**
     * 构造
     * @param strAddr 地址
     * @throws Exception
     * @email:835264047@qq.com
     */
    public ClientMacAddr(String strAddr) throws Exception {
        sRemoteAddr = strAddr;
        ds = new DatagramSocket();
    }
    
    /**
     * 组装并发送数据报包
     * @param bytes 缓冲数据
     * @return 组装的数据报包
     * @throws IOException
     * @author:JeffXu
     * @email:835264047@qq.com
     */
    protected final DatagramPacket send(final byte[] bytes) throws IOException {
        DatagramPacket dp = new DatagramPacket(bytes, bytes.length, InetAddress.getByName(sRemoteAddr), iRemotePort);
        ds.send(dp);
        return dp;
    }
    
    /**
     * 接收数据报包
     * @return 接收的数据报包
     * @throws Exception
     * @author:JeffXu
     * @email:835264047@qq.com
     */
    protected final DatagramPacket receive() throws Exception {
        DatagramPacket dp = new DatagramPacket(buffer, buffer.length);
        ds.receive(dp);
        return dp;
    }
    
    /**
     * 得到查询命令的缓冲数据
     * @return 缓冲数据
     * @throws Exception
     * @author:JeffXu
     * @email:835264047@qq.com
     */
    protected byte[] GetQueryCmd() throws Exception {
        byte[] t_ns = new byte[50];
        t_ns[0] = 0x00;
        t_ns[1] = 0x00;
        t_ns[2] = 0x00;
        t_ns[3] = 0x10;
        t_ns[4] = 0x00;
        t_ns[5] = 0x01;
        t_ns[6] = 0x00;
        t_ns[7] = 0x00;
        t_ns[8] = 0x00;
        t_ns[9] = 0x00;
        t_ns[10] = 0x00;
        t_ns[11] = 0x00;
        t_ns[12] = 0x20;
        t_ns[13] = 0x43;
        t_ns[14] = 0x4B;
        
        for (int i = 15; i < 45; i++) {
            t_ns[i] = 0x41;
        }
        
        t_ns[45] = 0x00;
        t_ns[46] = 0x00;
        t_ns[47] = 0x21;
        t_ns[48] = 0x00;
        t_ns[49] = 0x01;
        return t_ns;
    }
    
    /**
     * 解析数据报包得到物理地址字符串
     * @param brevdata 待解析的数据报包缓冲数据
     * @return 解析出的物理地址
     * @throws Exception
     * @author:JeffXu
     * @email:835264047@qq.com
     */
    protected final String GetMacAddr(byte[] brevdata) throws Exception {
        int i = brevdata[56] * 18 + 56;
        String sAddr = "";
        StringBuffer sb = new StringBuffer(17);
        for (int j = 1; j < 7; j++) {
            sAddr = Integer.toHexString(0xFF & brevdata[i + j]);
            if (sAddr.length() < 2) {
                sb.append(0);
            }
            sb.append(sAddr.toUpperCase());
            if (j < 6)
                sb.append('-');
        }
        return sb.toString().trim().toUpperCase();
    }
    
    /**
     * 关闭数据报链接
     * @author:JeffXu
     * @email:835264047@qq.com
     */
    public final void close() {
        try {
            ds.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
    
    /**
     * 解析目标主机物理地址
     * @return 目标主机物理地址字符串
     * @throws Exception
     * @author:JeffXu
     * @email:835264047@qq.com
     */
    public final String GetRemoteMacAddr() throws Exception {
        // 如果为127.0.0.1,则获取本地MAC地址
        if ("127.0.0.1".equals(sRemoteAddr)) {
            InetAddress inetAddress = InetAddress.getLocalHost();
            // 貌似此方法需要JDK1.6。
            byte[] mac = NetworkInterface.getByInetAddress(inetAddress).getHardwareAddress();
            // 下面代码是把mac地址拼装成String
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < mac.length; i++) {
                if (i != 0) {
                    sb.append("-");
                }
                // mac[i] & 0xFF 是为了把byte转化为正整数
                String s = Integer.toHexString(mac[i] & 0xFF);
                sb.append(s.length() == 1 ? 0 + s : s);
            }
            // 把字符串所有小写字母改为大写成为正规的mac地址并返回
            return sb.toString().trim().toUpperCase();
        }
        byte[] bqcmd = GetQueryCmd();
        send(bqcmd);
        DatagramPacket dp = receive();
        String smac = GetMacAddr(dp.getData());
        close();
        
        return smac;
    }
}
